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प्रश्न
How do the valency and the atomic size of the elements vary while going from left to right along a period in the modern periodic table?
उत्तर
Variation in valency
On moving from left to right in the periodic table, valency increases up to 4 and then decreases.
- The electrons present in the last shell determine the valency of a particular element.
- If the number of valence electrons is less than or equal to 4, valency = number of valence electrons
- If the number of valence electrons is more than 4, valency = 8 - number of valence electrons
Variation in atomic size:-
Atomic size decreases along a period. This is because on moving across a period, the number of valence shells remains the same and the electrons increase by one unit. As a result, the nuclear charge increases and thus, the atomic radius decreases.
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संबंधित प्रश्न
An element Z has atomic number 16. Answer the following questions on Z:
1) State the period and group to which Z belongs
2) Is Z a metal or a non-metal?
3) State the formula between Z and hydrogen
4) What kind of a compound is this?
Name the element which is in first group and third period.
How does the tendency to gain electrons change as we go down in group 17 of the periodic table? Why does it change this way?
Where would you locate the element with electronic configuration 2, 8 in the modern periodic table?
An element 'X' (Atomic number – 20) burns in the presence of oxygen to form a basic oxide.
(a) Identify the element and write its electronic configuration.
(b) State its group number and period number in the Modern Periodic Table.
(c) Write a balanced chemical equation for the reaction when this oxide is dissolved in water.
Select the correct answer
Identify the metalloid
The elements of one short period of the periodic table are given below in order from left to right:
| Li | Be | B | C | O | F | Ne |
To which period do these elements belong?
The position of elements A, B, C, D and E in the periodic table are shown below:
|
Group 1 |
Group 2 |
Group 17 |
Group 18 |
|
|
|
|
D |
|
|
B |
C |
|
|
A |
|
|
E |
Which type of ion will be formed by elements A, B, and C.
Name the period which is the shortest period of the periodic table.
State the property trends in general of elements on moving down in a group of the periodic table.
